Nuclear Power plant infor

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Nuclear PowerHoang Tran, Ella Wong and Brooke Mayo


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Overview

Introduction to nuclear power Nuclear reactions

Nuclear power plant

Is nuclear energy safe?

Chernobyl and Three Mile Island

Physiological effects of ionizing radiation

Radiation sources and dose comparisons

Nuclear Waste

The Future of Nuclear Power


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Introduction to nuclear power

Uranium was discovered in 1789 by Martin

Klaproth, a German chemist, and named afterthe planet Uranus. The science of atomic radiation, atomic change

and nuclear fission was developed from 1895 to1945, much of it in the last six of those years

Over 1939-45, most development was focusedon the atomic bomb From 1945 attention was given to harnessing

this energy in a controlled fashion for navalpropulsion and for making electricity

Since 1956 the prime focus has been on thetechnological evolution of reliable nuclearpower plants.


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Economic Advantages

The energy in one pound of highly enriched

Uranium is comparable to that of one milliongallons of gasoline.

One million times as much energy in one poundof Uranium as in one pound of coal.

Nuclear energy annually prevents 5.1 milliontons of sulfur 2.4 million tons of nitrogen oxide164 metric tons of carbon

First commercial power plant, England 1956

17% of worlds electricity is from nuclear power


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Fission Reaction

A classic example of a

fission reaction is that ofU-235:

U-235 + 1 Neutron2 Neutrons + Kr-92 + Ba-

142 + E In this example, a stray

neutron strikes an atom ofU235. It absorbs the

neutron and becomes anunstable atom of U-236. Itthen undergoes fission.These neutrons can strikeother U-235 atoms to

initiate their fission.


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Nuclear Power Plant

The Pressurized Water

Reactor (PWR)

Boiling WaterReactor (BWR)


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Is Nuclear Energy Safe?


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Chernobyl Accident- April 26, 1986

Worlds worst nuclear power

plant accident Chernobyl in Ukraine onPripyat River Population 12,500; 120,000 in30 km radius

4 reactors (2 built in 1970s, 2in 1980s) Combination of design andoperator error during electricalpower safety check resulted incascade of events leading tocore breach of Reactor 4 withsubsequent chemical (notnuclear) explosion

Chemistry in Context, Chapter 7

http://www.world-nuclear.org/info/chernobyl/inf07.htm
http://www.world-nuclear.org/info/chernobyl/inf07.htmhttp://www.world-nuclear.org/info/chernobyl/inf07.htmhttp://www.world-nuclear.org/info/chernobyl/inf07.htmhttp://www.world-nuclear.org/info/chernobyl/inf07.htm


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http://www.greenfacts.org/en/chernobyl/ /UN Chernobyl Forum(2006)

http://en.wikipedia.org/wiki/Chernobyl_disaster

Chernobyl- Reactor 4 Site
http://www.greenfacts.org/en/chernobyl/http://en.wikipedia.org/wiki/Chernobyl_disasterhttp://en.wikipedia.org/wiki/Chernobyl_disasterhttp://www.greenfacts.org/en/chernobyl/


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Chernobyl AccidentInitial radiation released primarily I-131 (half life= 8days), later Cs-137 (half life= 30 years)

Children particularly susceptible to I-131. Thyroidtakes up I- to produce the hormone thyroxine (T4,growth/metabolism).

I-131 decays be beta emission with accompanyinggamma ray

If ingested, can cause thyroid cancer About 4000 cases of thyroid cancer in exposedchildren (2000), nine related deaths in this group

Preliminary evidence (2006) suggests increased risk ofleukemia and possibly other cancers in liquidator groupand others with higher exposure in the first year-Among some 600,000 workers exposed in the first year,the possible increase in cancer deaths due to thisradiation exposure might be up to a few percent.

Chemistry in Context, Chapter 7http://www.world-nuclear.org/info/chernobyl/inf07.htm


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Chernobyl Accident Otherwise, UN report (2000)-there is no scientificevidence of any significant radiation-related health effectsto most people exposed No evidence of increase in birth defects, abnormalpregnancies, or reduced fertility Secondary effects- fatalism, mental health problems,smoking, alcohol abuse, general poor health and nutrition Surrounding farmland (1000 square miles) not farmable

due to high Cs-137 (exception, one small area in Belarus) High levels of Cs-137 found down wind in reindeer meatin Scandinavia Contamination effects on plants/animals within 30 km Contamination of nearby water bodies and fish


http://www.greenfacts.org/en/chernobyl/
http://www.world-nuclear.org/info/chernobyl/inf07.htmhttp://www.greenfacts.org/en/chernobyl/http://www.greenfacts.org/en/chernobyl/http://www.greenfacts.org/en/chernobyl/http://www.world-nuclear.org/info/chernobyl/inf07.htmhttp://www.world-nuclear.org/info/chernobyl/inf07.htmhttp://www.world-nuclear.org/info/chernobyl/inf07.htm


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Three Mile Island- March 28, 1979

Near Harrisburg, Pennsylvania Most serious US nuclear plant incident Valve malfunction and lost coolant with partialmeltdown Some radioactive gas released, no fatalities

No significant increase in cancer deaths in exposedpopulation Damage largely contained China Syndrome released 12 days before Construction of new nuclear plants shortly after

Resulted in broad changes in the nuclear powerindustry and NRC regarding emergency response,operator training, engineering/design criteria, radiationprotection, and oversight to enhance safety

Nuclear Energy- US Experience

Chemistry in Context, Chapter 7http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html

http://en.wikipedia.org/wiki/Three_Mile_Island_accident
http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://en.wikipedia.org/wiki/Three_Mile_Island_accidenthttp://en.wikipedia.org/wiki/Three_Mile_Island_accidenthttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htmlhttp://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html


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Safety of Nuclear Plants

Steel-reinforced concrete and a dome-shaped

containment buildings surround all US reactors (innerwall several feet thick and outer wall at least 15 inchesthick) Designed to withstand hurricanes, earthquakes, highwinds

Reactors have detectors to quickly shut down in eventof tremor (about 20% are in regions with seismicactivity like Pacific Rim)In considering safety, must address

Faults in plant design Human error Risks associated with terrorism/political instability

Chemistry in Context, Chapter 7


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No observable effect (< .25 Gy)- .25 Gy is nearly 70 times

average annual radiation exposure!White blood cell count drops (.25 to 1 Gy)Mild radiation sickness (1 to 2 Gy absorbed dose) Nausea and vomiting within 24 to 48 hours Headache

Fatigue WeaknessModerate radiation sickness (2 to 3.5 Gy) Nausea and vomiting within 12 to 24 hours Fever

Hair loss Vomiting blood, bloody stool Poor wound healing Any of the mild radiation sickness symptoms Can be fatal to sensitive individuals

Chemistry in Context, Chapter 7http://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptoms

Physiological Effects of Acute Radiation Exposure
http://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptomshttp://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptomshttp://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptomshttp://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptoms


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Severe radiation sickness (3.5 to 5.5 Gy)Nausea and vomiting less than 1 hour after exposure Diarrhea High fever

Any symptoms of a lower dose exposure About 50% fatality

Very severe radiation sickness (5.5 to 8 Gy) Nausea and vomiting less than 30 minutes after exposure

Dizziness Disorientation Low blood pressure Any symptoms of a lower dose exposure > 50% fatality

Longer term or chronic radiation effects include geneticmutations, tumors/cancer, birth defects, cataracts, etc.

Chemistry in Context, Chapter 7http://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptoms
http://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptomshttp://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptomshttp://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptomshttp://www.mayoclinic.com/health/radiation-sickness/DS00432/DSECTION=symptoms


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www.epa.gov/rpdweb00/docs/402-k-07-006.pdf
http://www.epa.gov/rpdweb00/docs/402-k-07-006.pdfhttp://www.epa.gov/rpdweb00/docs/402-k-07-006.pdfhttp://www.epa.gov/rpdweb00/docs/402-k-07-006.pdfhttp://www.epa.gov/rpdweb00/docs/402-k-07-006.pdfhttp://www.epa.gov/rpdweb00/docs/402-k-07-006.pdfhttp://www.epa.gov/rpdweb00/docs/402-k-07-006.pdfhttp://www.epa.gov/rpdweb00/docs/402-k-07-006.pdfhttp://www.epa.gov/rpdweb00/docs/402-k-07-006.pdf


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Source Dose(mrem)

Chest X-ray 10

5-hour plane flight 3

Live within 50 miles of coal-firedpower plant for 1 year

.03

Live within 50 miles of a nuclear

plant for 1 year

.009

US Average Annual Whole BodyRadiation Dose

360

Radiation Dose Comparisons

Chemistry in Context, Chapter 7http://www.who.int/ionizing_radiation/env/cosmic/en/index1.html


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Nuclear Waste

Challenges in the storage of spent reactor fuel

Waste

Contains radioactive fission products

Can be hazardous for thousands of years Half-life of Pu-239 is 24,110 years

Fission products, if released, can build up inthe body and be fatal


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Types of Nuclear Waste

High-level radioactive waste (HLW)

Long half-lives of radioisotopes

Requires permanent isolation

Mixed waste because hazardous chemicals &radioactivity

National risk because the waste could beextracted and used to make nuclear weapons

From nuclear power plants

Spent Nuclear Fuel (SNF): radioactive material

remaining in fuel rods after its used togenerate power in nuclear reactor

Contains Pu-239


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Types of Nuclear Waste

Low-level radioactive waste (LLW)

Waste with smaller amounts of radioactivematerials

No spent nuclear fuel

Includes contaminated lab clothing, gloves, and

tools (radioactivity levels are low)

90% of nuclear waste is LLW not HLW


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Risks & Benefits of Nuclear Power

Risks associated with energy produced by nuclear powerare less than from coal-burning plants.


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Risks & Benefits of Nuclear Power

Coal-fired electric plants(one 1000 MW plant) Nuclear plants(one 1000 MW plant)

releases 4.5 million tons ofCO2

produces 70 ft3 ofHLW/year

produces 3.5 million ft3 of

waste ash/year

no CO2 released

releases 300 tons of SO2and ~100 tons NOx/day

no acidic oxides of sulfurand nitrogen released

releases Uranium andThorium from coal


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Nuclear Power plant infor

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